重庆大学学报2017，Vol.40Issue(1)：76-85,10.DOI:10.11835/j.issn.1000-582X.2017.01.009
硼对第二代镍基单晶高温合金显微组织的影响
Effects of boron on the microstructure of second generation Ni-based single crystal superalloy
摘要
Abstract
Boron (B)is added into single crystal superalloys as a micro-alloying element to strengthen low angle grain boundaries.However,there are limited systematic investigations about the effect of B on the microstructures of single crystal superalloy.We studied the influences of B on phase transition temperature,(γ+γ′)eutectic and borides by analyzing the quantitative characterization of the as-cast and heat-treated microstructures of 3 kinds of second generation Ni-based single crystal superalloys DD11 with various additions of B (mass fraction of 0,0.01%and 0.02%).The results indicate that increasing B addition can significantly decrease the solidus and liquidus temperature and enhance the volume fraction of (γ+γ′)eutectic.The borides of M3 B2 are not observed in the alloy with 0.01 % B addition.However,when the B addition is 0.02%,the script-like borides are precipitated in the interdendritic region and the incipient melting point is decreased,and thus the volume fraction of residual eutectic is significantly improved.The script-like borides are rich in Cr,Mo and W,which decreases the solid solution strengthening effect,and thus creep properties of the alloy may be significantly decreased.This study would be helpful for the understanding of B’s role in Ni-base single crystal superalloys and the optimization of B content.关键词
单晶高温合金/硼/相转变温度/硼化物/固溶强化效果Key words
single crystal superalloy/boron/phase transition temperature/boride/solid solution strengthening effect分类
矿业与冶金引用本文复制引用
赵云松,骆宇时,张剑,郭会明,方向,唐定中..硼对第二代镍基单晶高温合金显微组织的影响[J].重庆大学学报,2017,40(1):76-85,10.基金项目
国家重点基础研究发展计划资助项目（2010CB631201）。Supported by National Key Basic Research Program of China （2010CB631201）． （）
